There are various storages, for example, a hard disk drive, a memory card, and a USB flash drive as the data storage apparatus that stores data used by a host device, such as a computer. A file system called FAT is generally applied to such data storage apparatuses. The FAT file system provides a management area called a file allocation table in the data storage apparatus to manage the location of each recorded data. The file allocation table records management information provided for each file as a management object. The management information is generally cluster chain information representing the structure and a storage location of each file.
Since the information recorded in the file allocation table is of great importance, two file allocation tables of the identical contents are generally provided in the data storage apparatus. Even when one of the file allocation tables is somehow damaged, normal data reading and data writing operations are ensured by the use of the other file allocation table (see JP-A-H11-249968).
In the data storage apparatus adopting this file system, it is required to update the contents of the file allocation table a large number of times in the case of writing a large number of small files. Such frequent update of the file allocation table undesirably lowers the writing efficiency. In the data storage apparatus using the multiple file allocation tables, information of identical content is to be written multiple times. This further lowers the writing efficiency. This problem is not unique to the FAT file system but is commonly found in data storage apparatuses adopting any file systems requiring two or more records of identical management information, as well as the data storage apparatus adopting the FAT file system.